Review Request: BigInteger patch for efficient multiplication and division (#4837946)

Dr Heinz M. Kabutz heinz at
Mon Mar 4 22:37:28 UTC 2013

Whilst we're at it, could we also add an option, perhaps via
environment variable, to parallelize Karatsuba and other calculations?

Here's an article I wrote about the inefficiencies of BigInteger and
working out large numbers:


On 05/03/2013, Brian Burkhalter <brian.burkhalter at> wrote:
> Hi Alan,
> Thanks for the history: I was not myself aware of all that and it is good to
> know.
> Brian
> On Mar 4, 2013, at 1:44 PM, Alan Eliasen wrote:
>>   That's good to hear.  By the way, in case you didn't know the history
>> of this bugfix, the leading researcher in the world in Toom-Cook and
>> other techniques for high-performance multiplication, Marco Bodrato, and
>> his colleagues, reviewed my parts of the patch (Karatsuba and Toom-Cook
>> multiplication, Karatsuba and Toom-Cook squaring) and said they were
>> "very clean."  I also ran hundreds of gigabytes of test cases through it
>> (repeatedly,) taking many days, and cross-checked my multiplication
>> routines against several other packages including GMP and previous
>> versions of BigInteger.

Dr Heinz M. Kabutz (PhD CompSci)
Author of "The Java(tm) Specialists' Newsletter"
Sun Java Champion
IEEE Certified Software Development Professional
Tel: +30 69 75 595 262
Skype: kabutz

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